// 背景图片
bg-image($url)
    background-image:url($url + "@2x.png")
    @media (-webkit-min-device-pixel-ratio: 3),(min-device-pixel-ration: 3)
        background-image: url($url + "@3x.png")

// 不换行
no-wrap()
    text-overflow: ellipsis
    overflow hidden
    white-space nowrap

// 点击扩展区域
    extend-click()
        position: relative
        &:before
            content: ''
            position absolute
            top: -10px
            left: -10px
            right: -10px
            bottom: -10px
